fix missing private key for the hardcoded DevnetEtherbase

* do not panic if SigKey is not found
* save hardcoded DevnetEtherbase/DevnetSignPrivateKey into accounts so that SigKey can recover it

cmd/devnet/accounts/accounts.go

@@ -20,6 +20,14 @@ func init() {
 	core.DevnetSignKey = func(addr libcommon.Address) *ecdsa.PrivateKey {
 		return SigKey(addr)
 	}
+
+	devnetEtherbaseAccount := &Account{
+		"DevnetEtherbase",
+		core.DevnetEtherbase,
+		core.DevnetSignPrivateKey,
+	}
+	accountsByAddress[core.DevnetEtherbase] = devnetEtherbaseAccount
+	accountsByName[devnetEtherbaseAccount.Name] = devnetEtherbaseAccount
 }
 
 var accountsByAddress = map[libcommon.Address]*Account{}

cmd/devnet/transactions/tx.go

@@ -335,7 +335,12 @@ func signEIP1559TxsHigherThanBaseFee(ctx context.Context, n int, baseFeePerGas u
 
 		devnet.Logger(ctx).Info("HIGHER", "transaction", i, "nonce", transaction.Nonce, "value", transaction.Value, "feecap", transaction.FeeCap)
 
-		signedTransaction, err := types.SignTx(transaction, signer, accounts.SigKey(fromAddress))
+		signerKey := accounts.SigKey(fromAddress)
+		if signerKey == nil {
+			return nil, fmt.Errorf("devnet.signEIP1559TxsHigherThanBaseFee failed to SignTx: private key not found for address %s", fromAddress)
+		}
+
+		signedTransaction, err := types.SignTx(transaction, signer, signerKey)
 		if err != nil {
 			return nil, err
 		}